Fluid-pressure brake



Patented May 8, 1923-.'

NTV

GEORGE S. LANE, F SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO THEWESTINGHOUSEAIR BRAKE COMPANY, OF WILMERDING, PENNSYLVANIA, A CORPORATION 0FPENNSYLVANIA.

FLUID-PRESSURE BRAKE.

Application mea April so, 1921. seriai No. 465,936.'v

To aZZ'wLom z't 'may concer/n:

Be it known that I, GEORGE S. LANE, a citizen of the United States,residing at San Francisco, in the county of San Francisco and Stateof-Oa-lifornia, have invented new and useful Improvements in Fluid-Pressure Brakes, of which the following is a specification.

This invention lrelates to Huid pressure l0 brakes, and moreparticularly to a uid pressure brake system for motor vehicles.

One object of my invention is to provide a compact brake controllingvalve device of few parts and adapted to be cheaply manufactured Otherobjects and advantages will appear in the following more detaileddescription of the invention.

In the accompanying drawings; Fig. l1 is a diagrammatic view of a Huidpressure brake system for a motor vehicle truck and a trailer, with myinvention embodied therein; Fig. 2a central sectional view of the brakecontrolling valve device for a motor `vehiclc truck; Fig. 3 aV centralsectional View of the brake controlling valve device for a trailer; andFig. 4 a central sectional view of the brake valve device.

As shown in Fig. 1, the truck brake equipment may comprise a diaphragmbrake cylinder 1, a reservoir 2 adapted to be maintained charged withfluid under pressure by way of supply pipe 3, a brake controlling valvedevice 4, and a brake valve device 5 preferably associated with thesteering wheel 6 and` steering post 7.

According to my invention, the brake controlling valve devlce 4 maycomprise a chambered casingv member 8, a cap member 9and a valve seatmember`10 which is screwed into the casing member 8 at its centralportion.

Within the casing, there isv provided a ilexible disk 11, preferably ofsoft rubber,`

the chamber 12 at one side being vconnected to a pipe 13 leading to thebrake valve-5 and the chamber 14 at the opposite side -being connectedto pipe 15, leading to the supply reservoir 2. 1

Centrally secured to the disk 11 is a valve stem 16, which extendsinto a`central bore provided in the valve seat member 10 and at the outer endof the'stem 16 is a valve head 17 adapted'to engage a seat provided.chamber 20 containin n'ected to a straight airpipe 21, leading to inthe member 10. Adjacent to the disk 11, the stem 16 is provided with acone valve 18 adapted to engage a corresponding seat in the lmember 10.

The bore in. the member 10, intermediate the valves 17 and 18 isconnected by pipe 19 to the diaphragm brake cylinder 1and the the valve17 is conber 14 by a pipe 24 to an auxiliary reservoir In this case, thedisk 11 is not provided with a restricted port. Otherwise, theconstruction, and lthe piping connections are the same as the truckcontrolling valve device.

The brake valve device 5 is preferably ofl the type set forth in myprior pending application, serial No. 448,884, filed Mach 1, 1921, andas shown in Fig..4, may comprise '1ov v a `casing containing a diaphragm30, subject on one side to the pressure of a spring 31, the compressiveforce of which may be adjusted by the rotation of a handle 32. Thediaphragm 30 operates a supply valve 33 for controlling communicationfrom pipe 13 to chamber 34, which is' connected to the straight air pipe21 and the diaphragm also operates an exhaust valve 35. v

The pipe 23 is connected to the reservoir supply pipe 3 between checkvalves 26 and 27, the check valve 26 preventing loss of pressure fromthe reservoir .2, in case of breakage of the pipe line 23, and the checkvalve' 27 preventing. back How from the res'- ervoir pipe line 23 tothepipe 28, through which fluid under pressure is supplied/from a sourceofpressure to thereservoui;

In operation, if it isdesired to e ect an roo application of the brakes,the handle of .the

brake valve 5 is turned to a position corresponding with the pressuredesired in the brake'cylinder.

If the spring 3l of the brake valve is adj usted by the movement of thebrake valve handle 32 fora pressure of thirt pounds, for exan'cple, thenthe supply va ve 33 of the brake valve will be opened to admit fluidfrom pipe 13 to the straightair pipe 21. Fluid under pressure will thenflow from the reservoir 2 through pipe 15 to chamber 14: and thencethrough the restricted port in the tube 22 to chamber 12. It the rate atwhich fluid is supplied from chamber 12 through the brake valve 5 to thestraight air pipe 21 is less than the rate at which fluid can flowthrough the restricted port,` Athen the disk 11 will remain in thenormal position, als shown in Fig. 2iand fluid under pressure will besupplied through the straight air pipe 21 to chamber 20ct the brakecontrolling valve device f1 and thence past the open valve, 17 to pipe19 and the diaphragm brake cylinder 1.

It the rate of flow to thestraight air pipe exceeds the capacity oftherestricted port through the disk 11, then the disk will be ilexed bythe greater fluid pressure in chamber 14, so as to operate the stem 16and close the valve 17, at the same time opening the valve 18. Fluidunder pressure will now flow directly from thev reservoir 2, throughchamber 14 to the brake cylinder 1.

The reduction in pressure in the reservoir 2 by flow to the brakecylinder produces a reduction in pressure in the reservoir line 23 byback flow of the higher pressure in said line through the check Valve-26 to the reservoir and as a consequence, the disk 11 of the brakecontrolling valve device on automatically operate to open a direct comlmunication from the reservoir to the brake cylinder by way of the valve18, at the same time causing quick serial action on the trailer. Y

When the pressure in the straight air pipe 21 has been increased to thesetting of the brake valve 5, the supply. valve 33 of the brake-valvewill close.,` permitting. the fluid pressures on opposite sides ofthedisk V11 to equalize, so that the disk will be maintained/fin itsnormal position through the tendency of the disk, to flatten out in adirectionto seatthe valve 18.l

If there should be any leakagek from the brake cylinder orthe straightair pipe 21', the brake valve will automatically operate to restore thepressure to the setting of the brake valve.

The brakes may be released by moving the brake valve to releaseposition, in which iluid is releasedv from the brake' cylinder throughthe straight air pipe 21 and the exhaust port of the brake valve.

0n the trailer, when the system is charged with fluid under pressure,the fluid at reservoir pressure supplied to the pipe 23 flows to chamber12 of the brake controlling valve device 4J and the pressure of fluid insaid chamber then acts 0n the disk 11 to force the peripheral seatportion away from its normal seat on the cap 9, so that fluid issupplied past the disk to the cli-amber 14, charging the auxiliaryreservoir 25 *with iluid under pressure.

When the brakes are applied by operating the brake valve 5 on the truck,fluid supplied to the straight air pipe 21 flows past the open valve 17to the pipe 19 and thelbruke cylinder l on the trailer.

Since the fluid pressures on opposite sides of the disk 11 remainbalanced normally, the brakes are normally applied by iuid suppliedthrough the straight air pipe. If, however, the trailer should breakaway from the truck or should the pipe 23 become broken 'from any othercause, the sudden reduction in' pressure thus produced in the chamber 12of the brake controlling valve device will cause the disk 11 to be movedby the higher pressure in chamber 14, so as to operate the stem16,.thereby closing the valve 17 and opening the valve 18. t

Fluid under pressure is thus supplied from the auxiliary reservoir 25past the valve 18 to the brake lcylinder to effect an application of thebrakes. f

The disk 11 being of soft rubber, 'if the pipe 1? on the truck shouldbreak or should a sudden reduction in pressure in chamber 12be otherwiseproduced, t he disk 11 will be flexed so as to seat against the innerwall of the cap 9, and seal o' the restricted port through the disk.This action then prevents loss of pressure from the reservoir 2 and alsofrom the brake cylinder.

In this case, the'brakes may be released lby bleeding the reservoir `2,so as to permit I claim as new and desire4 to secure by Letters Patent`is: 1. In a fluid pressure brake, the combination with a .brake cylinderand a. straight air pipe, of a brake controlling Valve device comprising.ft-flexible resilient disk and a valve operated bysaid disk/forcontrolling communication from vthe straight air pipe to the brakecylinder. f

2. In a Huid pressure brake, the combinatipn with a brake cylinder, of abrake controlling valve device comprising a marginally free exibleresilient disk and means. operated by said disk for controlling thesupply of fluid to the brake cylinder.

3. In a fluid pressure brake, the combination with a brake cylinder, vofa brake controlling valve device comprising means for controlling thesupply of fluid tothe i brake cylinder and a flexible disk having itsmarginal portion unconllned and operated by fluid under pressure foractuating said means.

4.`In a. fluid pressure brake, thecomhination With a brake cylinder anda normally charged source of fluid under pressure, of a valve forcontrolling communication from said source to the brake cylinder and amarginally free flexible resilient disk operated by fluid unden pressurefor actuating said valve.

5. In a fluid pressure brake, the combination with a brake cylinder, astraight air pipe, and a source of fluid under pressure,`

of a valve for controlling communication from the straight air pipe tothe brake cyl inder` a vlave for controlling communication from saidsource of pressure to the brake cylinder, and a flexible resilient diskoperated by fluid under pressure for actuating said valves.

6. In a fluid pressure brake, the combination with a brakecylinder, astraight air pipe, and a source of fluid under pressure, of a. valve forcontrolling communica-tion from the straight air pipe to the brake`cylinder, a valve for controlling communication from said source ofpressure to the brake cylinder, and a flexible resilient disk normallyoperative to hold the straight air pipe controlling valve openandoperative upon being flexed from normal position to close .said valveand open the source of pressure controlling valve. i

7. In a fluid pressure brake, the combination With a brake cylinder, astraight air pipe, and a source of Afluid under pressure,

of a flexible resilient disk having one side connected to the source ofpressure, means operated by said disk for controlling com.

muriication from thestraight air pipe and the source of fluid underpressure to the brake cylinder, and a brake valve device for controllingthe supply of fluid from the source of pressure through a restrictedport to the opposite-side of said disk and thence to the straight airpipe. y

8. In a fluid ressure brake1 thecombination with a rake cylinder,l of apipe adapted to be charged with fluid under ressure, a, reservoiradaptedtobe charged rom said pipe, a resilient disk having a marginal ,by saiddisk for controlling the supply of `1fluid to the brake cylinder.

9. In a fluidpressure brake, the combination with a brake cylinder, of'a pipe normally charged With fluid under pressure, a reservoir, aresilient disk subject to the opposing pressures of said pipe and thereservoir and adapted to be marginally flexed to permit the flow offluid :from said pipe to the reservoir, and means operated by saiddiskfor controlling the supply of fluid to the brake cylinder.

l0. In a duid pressure. brake, the combination with a brake cylinder, ofa pipe normally charged With fluid under pressure, a reservoir, aresilient disk subject to the opposing pressures of said pipe andthe-reservoir-and adapted to be marginally flexed to permit the dowof'fluid from said pipel to the reservoir` and means operated by the onsaid stem for controlling communication from the reservoir to the brakecylinder, and a valve on said stem for controlling communication fromthe straight air pipe to the brake cylinder.

12.- In a Huid pressure brake, the combination with a reservoir on avehicle, of a pipe connected to said reservoir and a brake controllingvalve-'device on a ltrailer vehicle 'operated upon a reduction inpressure in said reservoir'a-nd pipe forefl'ecting an application of thebrakes on the trailer vehicle.

13. In a fluid pressure brake, the combination with a reservoir on aleading vehicle and means for controlling the supply o f fluid from saidreservoir to ell'ect an application of the brakes on said vehicle, ofhapipe connected to said reservoir and a brake controlling valve device ona trailer vehicle connected to said pipe and operated. upon a reductionin pressure in said reservoir and pipe for effecting an application ofthe brakes lon the trailer vehicle. l

In testimony whereof I havev hereunto set

